1. Field of the Invention
This invention relates to devices for applying clips to mammalian vessels and tissue and more particularly to a safety locking mechanism for such a clip applying device.
2. Prior Art
Modem surgery may be identified as laparoscopic surgery, which may be defined as minimally invasive surgery upon a patient, utilizing small or miniaturized medical devices by which body tissue is cut, removed or cauterized by small manipulable devices through small incisions or openings within the patient""s body. A grasper or dissector is one such tool for that type of surgery. Such a device may be utilized to grab, dissect, treat or move tissue out of the surgical situs where other tissue may be surgically treated.
There is a need for a readily manipulable device for the grasping and or crimping/sealing of tissue by the single hand of an operating surgeon.
It is an object of the present invention to provide a grasper, dissector or crimper which is an improvement over the prior art.
It is a further object of the present invention to provide a safety mechanism for such a grasper or crimper to control the loading of such a device.
It is another object of the present invention to prevent problems of loose clips or a loose cartridge.
It is another object of the present invention to provide a grasper, dissector or crimper which will not be overloaded and wherein jamming of its jaws and its clips will be prevented.
It is yet another object of the present invention to provide a simple clip feed through mechanism with a safety lock which overcomes and helps avoid the problems of the prior art.
The present invention relates to a clip applying apparatus utilized in medical procedures for pinching off and clinching together mammalian tissue. Such a clip applying device comprises a pistol shaped housing at a proximal end thereof, with an elongated barrel extending therefrom, the barrel having a distal end from which extends a pair of pincher jaws. The pistol-shaped housing has a bore extending therethrough for receipt of an inner sleeve. The inner sleeve extends through the housing and itself receives a clip loaded cartridge from its proximalmost end.
The housing has a fixed handle portion extending downwardly therefrom, and a trigger lever which is pivotably disposed in the housing and swings about an axis therebetween. An elongated ratchet plate is fixedly attached to the trigger lever. The elongated ratchet plate has a distal end with a plurality of ratchet teeth formed thereon. A bifurcated finger is fixedly attached to an upper end of the trigger lever, and is disposed within the housing about opposite sides of the inner sleeve. The bifurcated finger is disposed about a cylindrical portion of a distal bearing which slides forwardly and rearwardly about the inner sleeve. The distal bearing is connected via an elongated shaft to a housing to squeeze the pincher jaws closed.
An elongated lever interface arm has a lower end which is pivotably attached to the fixed handle of the housing at a midpoint thereof. The elongated lever interface arm has a distal end comprised of a second bifurcated finger arrangement which is disposed about opposite sides of a proximal bearing. The proximal bearing is disposed on the proximal end of the inner sleeve within the pistol shaped housing.
An elongated linkage bar is pivotably attached at a first end thereof, to the elongated ratchet plate. The linkage bar has an elongated slot disposed therein in an axial arrangement near its second or distal end. A pivot pin extends through a pivot hole in the elongated lever interface arm and into the axially directed slot near the distal end of the linkage bar. A coiled spring is arranged between the lowermost end of the fixed handle and an extension arranged on the upper end of the elongated ratchet plate. The coiled spring provides a biasing force against which the trigger lever must be pulled.
A ratchet pawl is arranged around the pivot axis on the lowermost or proximal end of the elongated lever interface arm. The ratchet pawl is arranged to engage the ratchet teeth on the distal end of the elongated ratchet plate.
The inner sleeve arranged within the bore of the pistol shaped housing, has an elongated slot arranged in an axially disposed orientation at a midpoint thereof An elongated lock key is pivotably disposed within the inner sleeve in the housing, about a key pivot axis, which axis is fixed within the inner sleeve cylinder. The pivotable lock key has an enlarged distalmost end which is arranged to pivot into and out of the bore of the inner sleeve, and within the axial slot within that in a sleeve. The proximal bearing is arranged to slide distally and proximally about the inner sleeve and radially adjacent the axial slot in the inner sleeve when the elongated lever interface arm is pivoted proximally and distally with respect to that inner sleeve.
When the trigger lever is in its fully opened configuration, the first bifurcated finger arrangement is in its proximalmost orientation. At the same time, the proximal bearing is at its forward or distalmost orientation. That means that the proximal bearing is now radially disposed adjacent and over the axial slot in the inner sleeve. This occurs only when the pivotable lock key has been pivoted downwardly and out of the way, so that the proximal bearing may slide distally over that axial slot.
When the pivotable locked key is pushed downwardly into the bore of the inner sleeve, with the proximal bearing covering the axial slot, the pivotable lock key cannot be pivoted radially outwardly from the bore of that inner sleeve. The pivotable lock key, as aforementioned, has an enlarged distalmost end, which end, in effect, prevents insertion of clip cartridges within the bore of the inner sleeve, thus effecting the prevention of inadvertent loading of subsequent clips until the clip applying device is empty and ready for such further clip loading.
When the trigger lever is pulled towards the fixed handle portion of the pistol shaped housing, the forward bifurcated finger arrangement pushes the distal bearing distally or forward, so as to actuate the jaw pinching mechanism. The elongated linkage bar is directed proximally as the elongated ratchet plate is pivoted about the first trigger axis. As the pivot axis in the elongated lever interface arm and the elongated linkage bar engage, the elongated lever interface arm is caused to pivot rearwardly. The rearward pivoting of the elongated lever interface arm effects rearward or proximal motion of the second bifurcated finger, thus moving the proximal bearing rearwardly about the inner sleeve. Displacement of the proximal bearing rearwardly exposes the axial slot in the inner sleeve, thus permitting the pivotable lock key to be pushed upwardly as a new cartridge is placed or pushed into the proximal end of the inner sleeve to load the clip device into the barrel.
The inner sleeve and its distalmost mechanism is permitted to rotate about its longitudinal axis. The proximal bearing being comprised of an annular ring covers the axial slot in the inner sleeve no matter which orientation the axial slot resides.
Thus what has been shown is a unique safety mechanism for a medical clip applying device permits access to and prevents access to the inner bore of the inner sleeve by a cartridge, thus preventing misuse of the medical clip applying device. The circumferential arrangement of the proximal bearing allows the sleeve to be rotated in any angular position while still effecting the safety lock mechanism.
Thus the invention comprises an elongated medical clip applying device having a hand holdable housing at a proximal end thereof and a barrel clip-dispenser at a distal end thereof for dispensing squeezable clips onto a mammalian tissue. The device includes a hollow inner sleeve arranged within the housing, the sleeve having a proximal end for receiving a clip feeder cartridge therein. A proximal bearing is slidably disposed about a proximal circumference of the inner sleeve. A trigger lever is attached to the housing, the trigger lever having a linkage bat thereon connected to a finger for moving the proximal bearing proximally and distally. A lock mechanism is arranged in the sleeve arranged to deny a clip feeder cartridge entry into the sleeve when the proximal bearing is adjacent the lock mechanism. The lock mechanism may comprise a pivotable key for blocking the hollow inner sleeve. The inner sleeve has an elongated slot therein which slot is arranged to receive the key so as to deny entry and receipt of the clip cartridge in the inner sleeve. The proximal bearing may enclose the entire circumference of a portion of the inner sleeve. The key may have an enlarged distalmost end for effecting the blocking of the inner sleeve. The key may have a proximal end which is pivotally connected by a pivot axis, to the inner sleeve. The finger may be bifurcated to engage the proximal bearing at two sides thereof.
The invention may also comprise a method of locking an elongated medical clip applying device to prevent inadvertent loading of a clip cartridge into an inner sleeve thereof, which sleeve and an extended distal barrel are supportively arranged in a housing of the device It comprises arranging a locking mechanism in a proximal portion of the sleeve in the housing; pulling a trigger lever on the housing to unlock the locking mechanism upon emptying of clips from a cartridge previously loaded into the sleeve and barrel; loading a clip cartridge into a proximal end of the sleeve; and releasing the trigger lever to advance the clip cartridge within the sleeve and barrel of the device. The method includes forming a slot in the inner sleeve at the proximal end thereof, for receipt of the locking mechanism; placing a pivotable key in the slot to effect passage of a clip cartridge within the sleeve; moving a bearing radially adjacent the key in the slot to prevent pivoting of the key from the slot and thereby effectively blocking the sleeve from further loading; moving the bearing from a position radially adjacent the slot and the key, to permit the key to be pivoted outwardly from the slot thereby permitting entry and passage of a clip cartridge therewithin.